class/System.Security/System.Security.Cryptography/ProtectedData.cs

   1 //
   2 // ProtectedData.cs: Protect (encrypt) data without (user involved) key management
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // (C) 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 #if NET_2_0
  31
  32 using System.Runtime.InteropServices;
  33 using System.Security.Permissions;
  34
  35 using Mono.Security.Cryptography;
  36
  37 namespace System.Security.Cryptography {
  38
  39         // References:
  40         // a.   Windows Data Protection
  41         //      http://msdn.microsoft.com/library/en-us/dnsecure/html/windataprotection-dpapi.asp?frame=true
  42
  43         public sealed class ProtectedData {
  44
  45                 private ProtectedData ()
  46                 {
  47                 }
  48
  49 // FIXME        [DataProtectionPermission (SecurityAction.Demand, ProtectData = true)]
  50                 public static byte[] Protect (byte[] userData, byte[] optionalEntropy, DataProtectionScope scope)
  51                 {
  52                         if (userData == null)
  53                                 throw new ArgumentNullException ("userData");
  54
  55                         // on Windows this is supported only under 2000 and later OS
  56                         Check (scope);
  57
  58                         switch (impl) {
  59                         case DataProtectionImplementation.ManagedProtection:
  60                                 try {
  61                                         return ManagedProtection.Protect (userData, optionalEntropy, scope);
  62                                 }
  63                                 catch (Exception e) {
  64                                         string msg = Locale.GetText ("Data protection failed.");
  65                                         throw new CryptographicException (msg, e);
  66                                 }
  67                         case DataProtectionImplementation.Win32CryptoProtect:
  68                                 try {
  69                                         return NativeDapiProtection.Protect (userData, optionalEntropy, scope);
  70                                 }
  71                                 catch (Exception e) {
  72                                         string msg = Locale.GetText ("Data protection failed.");
  73                                         throw new CryptographicException (msg, e);
  74                                 }
  75                         default:
  76                                 throw new PlatformNotSupportedException ();
  77                         }
  78                 }
  79
  80 // FIXME        [DataProtectionPermission (SecurityAction.Demand, UnprotectData = true)]
  81                 public static byte[] Unprotect (byte[] encryptedData, byte[] optionalEntropy, DataProtectionScope scope)
  82                 {
  83                         if (encryptedData == null)
  84                                 throw new ArgumentNullException ("encryptedData");
  85
  86                         // on Windows this is supported only under 2000 and later OS
  87                         Check (scope);
  88
  89                         switch (impl) {
  90                         case DataProtectionImplementation.ManagedProtection:
  91                                 try {
  92                                         return ManagedProtection.Unprotect (encryptedData, optionalEntropy, scope);
  93                                 }
  94                                 catch (Exception e) {
  95                                         string msg = Locale.GetText ("Data unprotection failed.");
  96                                         throw new CryptographicException (msg, e);
  97                                 }
  98                         case DataProtectionImplementation.Win32CryptoProtect:
  99                                 try {
 100                                         return NativeDapiProtection.Unprotect (encryptedData, optionalEntropy, scope);
 101                                 }
 102                                 catch (Exception e) {
 103                                         string msg = Locale.GetText ("Data unprotection failed.");
 104                                         throw new CryptographicException (msg, e);
 105                                 }
 106                         default:
 107                                 throw new PlatformNotSupportedException ();
 108                         }
 109                 }
 110
 111                 // private stuff
 112
 113                 enum DataProtectionImplementation {
 114                         Unknown,
 115                         Win32CryptoProtect,
 116                         ManagedProtection,
 117                         Unsupported = Int32.MinValue
 118                 }
 119
 120                 private static DataProtectionImplementation impl;
 121
 122                 private static void Detect ()
 123                 {
 124                         OperatingSystem os = Environment.OSVersion;
 125                         switch (os.Platform) {
 126                         case PlatformID.Win32NT:
 127                                 Version v = os.Version;
 128                                 if (v.Major < 5) {
 129                                         impl = DataProtectionImplementation.Unsupported;
 130                                 } else {
 131                                         // Windows 2000 (5.0) and later
 132                                         impl = DataProtectionImplementation.Win32CryptoProtect;
 133                                 }
 134                                 break;
 135                         case PlatformID.Unix:
 136                                 impl = DataProtectionImplementation.ManagedProtection;
 137                                 break;
 138                         default:
 139                                 impl = DataProtectionImplementation.Unsupported;
 140                                 break;
 141                         }
 142                 }
 143
 144                 private static void Check (DataProtectionScope scope)
 145                 {
 146                         if ((scope < DataProtectionScope.CurrentUser) || (scope > DataProtectionScope.LocalMachine)) {
 147                                 string msg = Locale.GetText ("Invalid enum value '{0}' for '{1}'.",
 148                                         scope, "DataProtectionScope");
 149                                 throw new ArgumentException (msg, "scope");
 150                         }
 151
 152                         switch (impl) {
 153                         case DataProtectionImplementation.Unknown:
 154                                 Detect ();
 155                                 break;
 156                         case DataProtectionImplementation.Unsupported:
 157                                 throw new PlatformNotSupportedException ();
 158                         }
 159                 }
 160         }
 161 }
 162
 163 #endif